The present invention relates to an information storage medium and a game image generation device.
A program that is executed by a device that includes a touch operation detection section that detects a touch operation on a screen, and a tilt detection section that detects the tilt of a housing of the device, has employed a first method that generates an image based on a housing tilt operation or a second method that generates an image based on a touch operation, for example.
JP-A-2006-148773 discloses detecting the tilt of a housing, and controlling reproduction of media contents based on the detection output (first method). As a specific example that uses the first method, a racing game that allows the player to control (adjust) the moving direction of a racing car in a game space by tilting a portable information terminal is disclosed.
According to the above specific example, when the user has turned the steering wheel to the right by tilting the portable information terminal to the right, for example, the user must return the portable information terminal to the horizontal state in order to return the steering wheel to the initial position. However, the user may tilt the portable information terminal to the left to a large extent when returning the portable information terminal to the horizontal state. Moreover, it is difficult to maintain the horizontal state, and an accurate reaction to the tilt may not be obtained depending on the hardware of the tilt detection section.
A racing game or the like may require a gear shift operation. In this case, an accurate reaction may not be obtained when using the first method for the above reasons. When it is necessary to perform a gear shift operation in addition to a steering operation, an acceleration operation, a deceleration operation, and the like, a gear shift operation button is normally fixed at a given position within the screen. According to the second method, the user must use three fingers at the same time when simultaneously performing the steering operation, the acceleration operation, and the gear shift operation, for example. This impairs operability.